Detrimental alteration of mesenchymal stem cells by an articular inflammatory microenvironment results in deterioration of osteoarthritis

Disease microenvironment preconditioning: An evolving approach to improve therapeutic efficacy of human mesenchymal stromal cells

Despite the tremendous success in preclinical models, the translation of human mesenchymal stromal cells (hMSCs) as a therapy in the clinic is not up to the expectation. Intrinsic factors (age, sex, health status, life style of the donor, source, cellular senescence, and oxidative stress in hMSCs), extrinsic factors (culture system, batch-to-batch variations, choice of biomaterials, cell processing and preservation protocols), and host microenvironment (inflammatory milieu, oxidative stress, and hypoxia in the recipient) compromise the overall therapeutic efficacy of the transplanted hMSCs. In recent times, the approach of 'Disease Microenvironment Preconditioning (DMP)' has garnered attention to overcome the host-associated attributes involved in compromised hMSCs therapeutic potential. In this review, we discuss various approaches of DMP of hMSCs by employing serum and other body fluids obtained from diseased patients/animals and small molecules, including cytokines such as IFN-γ, IL-6, IL-10, IL- β, TGF-β1, IL-1α, IL-1β, TNF-α, HMGB1, IL-17 A, and IL-8 which are associated with disease conditions. DMP strengthens hMSCs ability to adapt/acclimatize and respond more efficiently to the hostile microenvironment they encounter upon transplantation. DMP modulate hMSCs to withstand inflammation, survive under hypoxic and nutrient-deprived conditions, and resist oxidative stress. Evidence from various disease models ranging from cardiovascular and neurodegenerative disorders to autoimmune diseases and tissue injuries supports the role of DMP in improving hMSC survival, integration, and functional efficacy. While the potential of DMP to revolutionize MSC-based therapies is evident, challenges such as standardizing/optimizing protocols for preconditioning is essential. This review synthesizes current advancements in the approach of DMP aiming to propel the area of regenerative medicine.

Effects of Late-Passage Small Umbilical Cord-Derived Fast Proliferating Cells on Tenocytes from Degenerative Rotator Cuff Tears under an Interleukin 1β-Induced Tendinopathic Environment

BACKGROUND

Tendinopathy is a chronic tendon disease. Mesenchymal stem cells (MSCs), known for their anti-inflammatory properties, may lose effectiveness with extensive culturing. Previous research introduced "small umbilical cord-derived fast proliferating cells" (smumf cells), isolated using a novel minimal cube explant method. These cells maintained their MSC characteristics through long-term culture. Thus, the purpose of the present study was to assess the anti-inflammatory effects of late-passage smumf cells at P10 on tenocytes derived from degenerative rotator cuff tears in a tendinopathic environment.

METHODS

The mRNA expression with respect to aging of MSCs and secretion of growth factors (GFs) by smumf cells at P10 were measured. mRNA and protein synthesis in tenocytes with respect to the tenocyte phenotype, inflammatory cytokines, and matrix- degradation enzymes were measured. The inflammatory signal pathways involving nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) in tenocytes were also investigated. The proliferative response of degenerative tenocytes to co-culture with smumf cells over 7 days in varying IL-1β induced tendinopathic environments was investigated.

RESULTS

smumf cells at P10 showed no signs of aging compared to those at P3. smumf cells at P10, secreting 2,043 pg/ml of hepatocyte growth factor (HGF), showed a 1.88-fold (p = .002) increase in HGF secretion in a tendinopathic environment. Degenerative tenocytes co-cultured with smumf cells showed significantly increased protein expression levels of collagen type I (Col I) and the Col I/III ratio by 1.46-fold (p < .001) and 1.66-fold (p < .001), respectively. The smumf cells at P10 reduced both mRNA and protein expression levels of matrix metalloproteinases-1, -2, -3, -8, -9, and -13 in tenocytes and attenuated NF-κB (phosphorylated IκBα/IκBα and phosphorylated p65/p65) and MAPK (phosphorylated p38/p38 and phosphorylated JNK/JNK) pathways activated by IL-1β. Removal of IL-1β from the co-culture accelerated the growth of tenocytes by 1.42-fold (p < .001). Removal of IL-1β accelerated tenocyte growth in co-cultures.

CONCULSION

Late-passage smumf cells exert anti-inflammatory effects on tenocytes derived from degenerative rotator cuff tears under a tendinopathic environment, primarily through the secretion of growth factors (GFs).

Effects of Conditioned Media From Human Umbilical Cord-Derived Mesenchymal Stem Cells on Tenocytes From Degenerative Rotator Cuff Tears in an Interleukin 1β-Induced Tendinopathic Condition

Background

Evidence suggests that mesenchymal stem cells (MSCs) are safe for treating different tendinopathies. Synovial fluid is a pooled environment of biomarkers from the inflammatory and degenerative joint cavity. Understanding the effects of synovial fluid on MSCs is important, as it is the first microenvironment that administered MSCs encounter. Several studies have reported that exposure to osteoarthritic synovial fluid-activated MSCs increased the release of soluble factors; however, the paracrine effects of shoulder synovial fluid-stimulated umbilical cord-derived MSCs (SF-UC-MSCs) on tendinopathy have yet to be investigated.

Purpose

To assess the effects of the conditioned media from SF-UC-MSCs on tenocytes from degenerative rotator cuff tears in an interleukin-1β (IL-1β)-induced tendinopathic condition.

Study Design

Controlled laboratory study.

Methods

UC-MSCs were isolated and cultured from healthy, full-term deliveries by cesarean section. Tenocytes were isolated and cultured from patients with degenerative rotator cuff tears. Conditioned media were obtained from UC-MSCs stimulated with synovial fluid. To evaluate the gene expression of proinflammatory and anti-inflammatory cytokines, enzymes and their inhibitors, matrix molecules, and growth factors, the tenocytes were cultured with IL-1β and 50% of the conditioned media from the SF-UC-MSCs; quantitative, real-time, reverse transcriptase polymerase chain reaction was also performed. A prostaglandin E2 (PGE2) assay was performed to investigate the PGE2 level secreted by the tenocytes. Western blotting was performed to examine protein synthesis of collagen type I and III. Cell viability, senescence, and apoptosis assays were also performed.

Results

The conditioned media from the SF-UC-MSCs interfered with the inflammatory gene expression on tenocytes induced by IL-1β, but it increased the gene expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-3. Meanwhile, the conditioned media decreased the PGE2 level on cells induced by IL-1β. It did increase the type I/III ratio of gene expression and protein synthesis, mainly through the induction of type I collagen. Conditioned media of SF-UC-MSCs reversed senescence and apoptosis induced by IL-1β.

Conclusion

Study findings indicated that the conditioned media from SF-UC-MSCs had anti-inflammatory effects and cytoprotective effects on IL-1β-treated tenocytes from degenerative rotator cuff tears.

Clinical Relevance

UC-MSCs have useful potential for the treatment of tendinopathy in practice.

Roles of Microenvironment on Mesenchymal Stem Cells Therapy for Osteoarthritis

Osteoarthritis (OA) induced microenvironmental alterations are a common and unavoidable phenomenon that greatly exacerbate the pathologic process of OA. Imbalances in the synthesis and degradation of cartilage extracellular matrix (ECM) have been reported to be associated with an adverse microenvironment. Stem cell therapy is a promising treatment for OA, and mesenchymal stem cells (MSCs) are the main cell sources for this therapy. With multispectral differentiation and immunomodulation, MSCs can effectively regulate the microenvironment of articular cartilage, ameliorate inflammation, promote regeneration of damaged cartilage, and ultimately alleviate OA symptoms. However, the efficacy of MSCs in the treatment of OA is greatly influenced by articular cavity microenvironments. This article reviews the five microenvironments of OA articular cavity, including inflammatory microenvironment, senescence microenvironment, hypoxic microenvironment, high glucose microenvironment and high lipid environment, focus on the positive and negative effects of OA microenvironments on the fate of MSCs. In this regard, we emphasize the mechanisms of the current use of MSCs in OA treatment, as well as its limitations and challenges.

Protective effects of emodin on subchondral bone and articular cartilage in osteoporotic osteoarthritis rats: A preclinical study

BACKGROUND

Osteoporotic osteoarthritis (OP-OA) is a severe pathological form of OA, urgently requiring precise management strategies and more efficient interventions. Emodin (Emo), an effective ingredient found in the traditional Chinese medicine rhubarb, has been dEmonstrated to promote osteogenesis and inhibit extracellular matrix degradation. In this study, we aimed to investigate the interventional effects of Emo on the subchondral bone and cartilage of the knee joints in OP-OA model rats.

METHODS

Thirty-two SD rats were randomly and equally divided into sham, OP-OA, Emo low-dose, and Emo high-dose groups. Micro-CT scanning was conducted to examine the bone microstructure of the rat knee joints. H&E and Safranin O and Fast Green staining (SO&FG) were performed for the pathomorphological evaluation of the rat cartilage tissues. ELISA was used to estimate the rat serum expression levels of inflammatory factors, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Additionally, the CCK-8 assay was utilized for determining the viability of Emo-treated BMSCs. Western blot and real-time PCR analyses were also employed to measure the bone formation indexes and cartilage synthesis and decomposition indexes. Lastly, the osteogenic and chondrogenic differentiation efficiency of the BMSCs was investigated via Alizarin Red and Alcian Blue staining.

RESULTS

Emo intervention alleviated the bone microstructural disruption of the subchondral bone and articular cartilage in the OP-OA rats and up-regulated the expression of bone and cartilage anabolic metabolism indicators, decreased the expression of cartilage catabolism indicators, and diminished the expression of inflammatory factors in the rat serum (P<0.05). Furthermore, Emo reversed the decline in the osteogenic and chondrogenic differentiation ability of the BMSCs (P<0.05).

CONCLUSION

Emo intervention mitigates bone loss and cartilage damage in OP-OA rats and promotes the osteogenic and chondrogenic differentiation of BMSCs.

Effect of umbilical cord blood-mononuclear cells on knee osteoarthritis in rabbits

BACKGROUND

To investigate the effect and underlying mechanism of umbilical cord blood-mononuclear cells (UCB-MNCs) in treating knee osteoarthritis (KOA) in rabbits.

METHODS

A rabbit KOA model was prepared by anterior cruciate ligament transection (ACLT). Fifty New Zealand white rabbits were randomly divided into the control group, model group, sodium hyaluronate (SH) group, platelet-rich plasma (PRP) group and UCB-MNC group. Knee injections were performed once a week for five consecutive weeks. The gross view of the knee joint, morphology of knee cartilage and structural changes in the knee joint were observed on CT scans, and graded by the Lequesne MG behavioral score and the Mankin score. TNF-α and IL-1β levels in the synovial fluid of the knee were measured by the enzyme-linked immunosorbent assay (ELISA). Expression levels of MMP-13 and COL-II in the knee cartilage were detected by Western blotting and qRT-PCR.

RESULTS

The Lequesne MG behavioral score and the Mankin score were significantly higher in the model group than those in the control group (P < 0.05). Rabbits in the SH, PRP and UCB-MNC groups had sequentially lower scores than those in the model group. Imaging features of KOA were more pronounced in the model group than in the remaining groups. CB-MNC significantly relieved KOA, compared to SH and PRP. Significantly higher levels of TNF-α and IL-1β in the synovial fluid of the knee, and up-regulated MMP-13 and down-regulated COL-II in the knee cartilage were detected in the model group than in the control group. These changes were significantly reversed by the treatment with SH, PRP and UCB-MNCs, especially UCB-MNCs.

CONCLUSION

Injections of UCB-MNCs into knees protect the articular cartilage and hinder the progression of KOA in rabbits by improving the local microenvironment at knee joints.